Some Hibiscus heterophyllus of South-east Queensland

AUSTRALIAN NATIVE PLANT SOCIETY

HIBISCUS AND RELATED GENERA STUDY GROUP

JUNE 2013 NEWSLETTER NO. 29 ISNN 1488-1488

EDITORIAL by GUEST EDITORS Dr Dion Harrison & Geoff Keena

Geoff Harvey has asked for a guest editor for this issue, while he continues to focus on recovery from a lengthy period of illness and treatment. In this issue, there are two articles on destruction of habitat for two species of Malvaceae: - River Hibiscus, Radyera farragei, growing in and around Alice Springs, Northern Territory - Native Hibiscus, Hibiscus heterophyllus, growing in the south-east of Queensland. This newsletter begins with a continuation by Alex Nelson of thought provoking information on Radyera farragei. Part 1 was in the last newsletter, Newsletter 28. It is interesting to note that, in the second article, two of the three weed species destroying Hibiscus heterophyllus in south-east Queensland are Class 3 declared pest plants under Queensland legislation and one is a Weed of National Significance but the third, Morning Glory, Ipomeae cairica, is not yet a declared species under Queensland legislation. This plant has certainly devastated, in a relatively short time, an area that we visit frequently. In this population of native hibiscus, there are plants on either side of the road but Morning Glory has not been deterred by the wide road dividing the stands of hibiscus as plants are being smothered that are quite some distance from each other and which are even separated by the road. We would appreciate any comments from our members on destruction of habitat for local Malvaceae species and this would be featured in future newsletters. As both Radyera farragei and Hibiscus heterophyllus occur in a range of locations, any information on the condition of other habitats would be especially useful. The other article is a follow-up to the information presented by Geoff Harvey on Hibiscus ‘Pink Ice’ and Hibiscus ‘Wirruna’ in Newsletter 22/23b. These native hibiscus were our first crosses to feature in written records and we have been fortunate to have information by the two members of our group who developed these cultivars, as well as another photograph of each plant growing in South Australia. We would love to hear from anyone growing these plants. For those wishing to grow ’Pink Ice’ or ‘Wirruna’, please let Colleen know (colleenkeena@pobox.com) how many plants of each you would like and she will try to see if she can organise plants. She will advise you of when the plants would be ready. We hope to see members at the ANSPA Conference in August. Please introduce yourself to Dion if possible. He will be presenting a paper ‘Breeding and Developing Australian Species: a Geneticist's Perspective’. Native hibiscus will be one of the featured plants. Dion & Geoff

MORE IMAGES OF MORNING GLORY

Morning Glory on road edge, with shoots spreading out Closeup of Morning Glory on Hibiscus heterophyllus

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River Hibiscus, Radyera farragei, in Alice Springs – the road to extinction. Alex Nelson, Central Australia

PART 2 Ross Highway roadside. Mature River Hibiscus plants can withstand direct competition with exotic grasses for an indefinite period. A good example of this is provided by a cluster of these plants occurring by the side of the Ross Highway adjacent to the Todd River just south of Alice Springs. The exact location is 1.1 km past the roundabout on the east end of the John Blakeman Bridge. The River Hibiscus plants are growing in a thicket of old “Prickly Wattle” (Acacia victoriae), the latter supporting extensive mistletoe infestations, all surrounded and immersed in a thick understorey of tall rank buffel grass. The proliferation of mistletoe is a good indication this site has avoided being burnt for many years. I took photographs of this site in the winter of 1998; and it remains essentially unchanged to the present time. The mature River Hibiscus plants appear capable of competing successfully with buffel grass but suffer a significant disadvantage in recruitment of new generations of plants, as there is very little opportunity for seedlings to germinate in these conditions.

River Hibiscus in 1998 beside the Ross Highway Mistletoe Roe Creek. Another site of interest is the east bank of Roe Creek about 100 metres upstream of Honeymoon Gap, 15 km west of Alice Springs. I stumbled over this location while taking a break during a bicycle ride along this road in August 1998, and it proffered some interesting observations. The site had been burnt several years earlier – I’m aware of a bushfire in this vicinity circa 1990 or 1991, and presumably it was the event that influenced the response of the vegetation I noted in 1998. The impact of the bushfire had been variable across the area – in parts the intensity had been sufficient to kill a swathe of Acacia victoriae shrubs but had not burnt them to cinders. The buffel grass had subsequently fully recovered and there was a new fuel load sufficient to kill juvenile shrubs outright in another fire – buffel grass was now the dominant mono-specific vegetation type although there were a few River Hibiscus plants scattered across the area that had also recovered from the fire a few years earlier. Adjacent to this zone were patches where it was evident the bushfire had burnt more intensely as several large River Red Gums (Eucalyptus camaldulensis) were severely damaged or been killed outright. More telling were the swathes of wildflowers colonizing bare areas of ground where even the buffel grass had been killed by the heat generated by their own fuel load, indicating the bushfire had occurred during hot windy conditions. The heat of the fire had apparently sterilized the seed bank in the soil and it had taken most of the decade for vegetation of any kind to re-colonize these patches. However, Central Australia was experiencing a wet winter in 1998, conditions which favoured the growth of herbaceous wildflowers. It was noticeable that where buffel grass had regrown there was a sharp reduction in the prevalence and diversity of the wildflowers. Clumps of River Hibiscus occurred in a scattered distribution over the severely burnt zone; these mature plants had staged a full recovery. I was unable to tell if their numbers had been reduced by the bushfire (see photos taken after fire in Part 1).

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However, there was a significant recruitment of seedlings that had germinated in response to the favourable conditions of bare soil surfaces and frequent winter rainfall. Another point of interest was the presence of some plant pots located near the base of a River Red Gum tree, in some of which were the remains of long dead River Hibiscus plants. Someone had apparently tried to transplant some of these plants several years previously but had abandoned the attempt. I returned to this site several years later (the exact date was not recorded) some time following the exceptionally wet years of 2000 and 2001. All of the area had reverted to a ground-cover of dense buffel grass, and the presence of other minor plant species was minimal.

River Hibiscus plants in drought conditions in 2009(left above); last natural plant in Alice Springs urban area Old Heffernan Road Crossing. The largest population of River Hibiscus close to Alice Springs I know of is found on the north bank of the Todd River, southeast of Alice Springs. They are growing on Crown Land where access is gained by travelling the Ross Highway to a dirt road turnoff 4.3 km from the roundabout at John Blakeman Bridge. The dirt road proceeds about 0.7 km to a crossing of the Todd River, which once used to link to Heffernan Road on the south side but is now cut off to vehicular traffic. On the river’s north bank the road is intersected by a bush track that runs along the riverbank; and by proceeding upstream about 50 metres one will encounter the majority of River Hibiscus growing in this vicinity. During 1998 I frequently cycled past this location and couldn’t help noticing the abundance and vigour of these plants; indeed, it was this site that alerted me to just how much the presence of River Hibiscus in general had vanished elsewhere along the Todd River. Upon closer inspection of this site I found numerous healthy mature plants, responding vigorously to the conditions of a wet winter. Equally I found large numbers of seedlings, on a scale much greater than I recall seeing anytime previously. It was obvious the seedlings preferred bare soil surfaces with maximum exposure to sunlight to facilitate germination in favourable conditions – their prevalence was sharply reduced in the presence of other vegetation or leaf litter covering the ground. It appeared the main advantage of this location for the River Hibiscus was due to its proximity to the main dirt road and nearby bush tracks. The amount of off-road traffic, including motorbikes, horse-riding and camel tours, ensured much of the ground-cover vegetation (including exotic grasses) was reduced; and there was significant ponding of water run-off from the bare soil and tracks that augmented soil moisture for the River Hibiscus. Further away from this location there was a reduction of traffic and corresponding increase in vegetative cover – but a sharp reduction in the occurrence of River Hibiscus. This showed a paradoxical situation in which activities usually considered as environmentally destructive were actually facilitating the survival of the River Hibiscus where elsewhere this species is under severe pressure as a result of the encroachment of exotic grasses that had been introduced as a soil conservation measure! The exceptionally wet years of 2000 and 2001 resulted in massive vegetative growth and consequent fuel buildup across Central Australia. The following year was extremely dry, and inevitably there were massive wildfires across the region. The banks of the Todd River along the Ross Highway did not escape the ravages of fire, including the location where the River Hibiscus grew. A patch of land adjacent to these plants burnt fiercely enough to kill the buffel grass clumps. Serious damage was inflicted on some of the large trees in the vicinity, and also on some of the River Hibiscus. Fortunately the main population survived although their numbers appear to be reduced.

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An adaptive response. Further upstream from the main population of River Hibiscus near the old Heffernan Road crossing I found a solitary plant with seedlings that exhibited an ability to cope with competition from exotic grasses. They were growing by an abandoned track near the riverbank, surrounded by couch grass and dense leaf litter. I was intrigued to note there were a large number of seedlings that had emerged through this material, in complete contrast to the usual behaviour of River Hibiscus seedlings. By comparing some seedlings from this solitary plant with those from the main group, I observed the former had much thicker tap roots – this trait appeared to give the seedlings from the solitary plant a significant competitive advantage enabling them to cope with competition from the couch grass and leaf litter.

A solitary river hibiscus plant that successfully competed Seedlings from plant (left) with thicker tap roots with dense leaf litter and other plants, notably couch grass. Attempts to transplant these failed. Parent plant and progeny were destroyed by fire in 2002. I attempted to transplant a number of these seedlings into tubes but they all eventually failed. I also collected a quantity of seed. Unfortunately these unusual plants succumbed to the wildfires of 2002 – none appeared to survive and no seedlings have germinated in that vicinity since that time. Although the River Hibiscus persist in some numbers in the vicinity of the old Heffernan Road crossing their continued survival in the long term is potentially jeopardized by the action of local authorities to limit off-road activity in the area. Consequently there is a greater risk of their eventual loss due to increased grass growth that could fuel wildfires unless specific measures are undertaken to reduce this threat; however, this is unlikely as the problems afflicting this species remain unrecognized by local conservation authorities. Alice Springs urban area. While River Hibiscus still manages to cling to survival in a few isolated pockets on the banks of waterways outside of Alice Springs, the same cannot be said for the Todd River within the urban area of the town. A few individual plants persisted along the Todd River in town until quite recently but now I find only one that is likely to be a naturally occurring specimen. This solitary plant is near but quite separate from a small group of River Hibiscus established by Greening Australia volunteers several years ago. Aside from these plants, no River Hibiscus plants exist along the Todd River from the Alice Springs Telegraph Station to the north to beyond Heavitree Gap to the south of town – a distance of five kilometres. The reason for their demise became apparent from the fate of one River Hibiscus plant I observed in 2006. This individual was the last survivor along the Todd River between Heavitree Gap (the town’s southern entrance) and the Stott Terrace Bridge near the town centre. It was a large healthy plant located on the west bank across the river from the Olive Pink Botanic Garden, where I was working at the time. Responsibility for the management of the Todd River within the urban area rests with the Alice Springs Town Council; however, this is largely beyond the resources and expertise of the council to manage beyond a very basic level. Occasionally council workers effect temporary fire hazard reduction by slashing exotic grass growth by large tractor mowers; a very rough-and-ready means of achieving control but which makes almost no allowance for discriminating between exotic and native plant species. That was the fate of this particular River Hibiscus when I discovered to my amazement one day this beautiful plant had been slashed to ground level. Clearly the tractor operator had no idea this plant is an indigenous species. The slashing of this large plant provided an opportunity for five of its progeny, previously overshadowed by their parent, to commence growing vigorously. Judging by their size, they had probably germinated in response to the wet years of 2000 and 2001. It was obvious to me that the town council’s management practices were a directly contributing cause to the elimination of River Hibiscus in the urban area; accordingly I judged the prospects of survival for the five young plants were bleak.

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I undertook to lift three of them into large pots to grow at the Olive Pink Botanic Garden; if any survived, I intended to establish them on the grounds. Despite the OPBG’s proximity to the Todd River, there was at the time no River Hibiscus growing in its collection of Central Australian native plants. Initially two of the transplants survived but only one was established in the botanic garden, where it survived rather poorly for a few years. A difficulty I encountered was the reluctance on the part of the OPBG to accept plants with no established provenance but an exception was made in this case because of the situation outlined above. Since 2008 more River Hibiscus plants have been established near the OPBG’s boundary near the Todd River, where they continue to flourish. The eventual fate of the two young River Hibiscus plants left in situ was as expected – they were slashed and (like their parent plant) failed to recover. No seedlings have germinated at this position despite the near-record rainfall of 2010. One problem with slashing vegetation is that it results in a thick layer of mulch and leaf litter covering the ground, which inhibits the germination of River Hibiscus seeds. Conversely, the mowing of exotic grasses often invigorates these plants into new growth.

Plants established by Greening Australia; seedling in a pot; near South Terrace urban Alice Springs winter, 1998 Future prospects. The last naturally occurring River Hibiscus plant in Alice Springs grows on the east bank of the Todd River near the Wills Terrace Causeway, a short distance from my home. About two years ago I obtained a tip cutting from this plant, and to my surprise it struck easily under very basic conditions. It was lost due to carelessness on my part (I forgot to water it one very hot summer’s day) but I repeated the process during autumn last year. The new cutting did little during the winter but grew vigorously as the weather warmed in the spring. It is now a sizable plant in a large pot and has produced two flushes of flowers. It is currently under shelter in a shady position to avoid the extreme temperatures of this summer and is set to flourish with the onset of cooler conditions in several weeks time. In general the future of River Hibiscus in Central Australia is bleak; possibly this may also be the case further afield. The continued existence of this ancient native plant species is at severe risk due to the continued encroachment of exotic grasses in its natural habitat, a situation exacerbated by a complete failure on the part of official authorities to understand and act on this problem. There is also a possibility that the natural range of River Hibiscus will be reduced as a consequence of climate change, as it is a species that favours the conditions of cool wet winters. This species is a survivor of climate change in the past so presumably this alone is not an insurmountable problem; but combined with the onslaught of exotic grasses its future prospects for continued survival would seem more problematic. In Central Australia the prospect of recovering River Hibiscus populations under management is excellent but the ongoing failure to appreciate this species’ inexorable decline means that there is less likelihood of this being achieved using source material from locally provenanced plants. Perhaps most important, however, is that the ongoing demise of River Hibiscus in Central Australia is sounding an alarm so that we cannot continue to ignore the worsening threat to the inland environment of Australia posed by the spread of exotic grasses, especially buffel grass.

Plant in a public park, 2000; natural plant in Alice Springs urban area; seedling grown in a pot; last natural plant.

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WAYS THE POPULATION OF HIBISCUS HETEROPHYLLUS IS BE ING DESTROYED OR DAMAGED IN SOUTH-EAST QUEENSLAND

Colleen and Geoff Keena

1. BULLDOZER Removal by bulldozer has occurred in the following situations where there were populations of Hibiscus heterophyllus: i. acreage development ii. road widening iii. clearing in areas where road materials are stored. We do not feel, as yet, that this is a significant factor since most of the current sites where these activities have taken place are in rural areas with limited development and hence limited loss of Hibiscus heterophyllus. A subsequent visit to the site of the first image below, showed that these two plants of Hibiscus heterophyllus were no longer there. We had found that the smaller hibiscus shown below had interesting features. Fortunately, this was a site where material was gathered in Spring 2010 for oxalate analysis and cuttings of the smaller plant had been collected and successfully struck. While we were busy admiring the blooms, Dr Dion Harrison noticed that touching the underneath of the leaves was like feeling velvet. The feature I admired is shown below, as is the unusual characteristic that Dion observed.

HIBISCUS HETEROPHYLLUS SUBSEQUENTLY BULL-DOZED:

Before the bulldozer the bloom underside of the leaf 2. ROADSIDE SPRAYING Twice we have collected forms of Hibiscus heterophyllus within easy access of main roads. Both times, the plants had distinctive features and twice we have returned to the sites to find the plants were dead, apparently from having been sprayed. One of these sites was in N.S.W., however the other was in south-east Queensland. We had collected cuttings (from both sites) and successfully struck these. The plant collected in south-east Queensland has been called Hibiscus heterophyllus ‘Mt Crosby Cliffs’, after the area where it was found. We were first drawn to the markings on the blooms (image below) however once we had this plant established, other features became apparent. One was that flowers could occur over a longer period than any other plants in the original location. The feature that we did not particularly notice at first was the almost prickle-free stems, as shown below. We first realised how few ‘prickles’ there were when seedlings showed the same characteristic. Other characteristics that became evident in seedlings were the unusual marking on the petals and blooms which could be much larger than any previously known plants, either species or crosses.

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HIBISCUS HETEROPHYLLUS SUBSEQUENTLY SPRAYED:

Plant collected from Mt Crosby Cliffs; almost prickle-free stem of this plant; seedling from this plant 3. AGGRESSIVE WEEDS While bull-dozers and roadside spraying have killed plants of Hibiscus heterophyllus with desirable characteristics, the risk of these impacting on Hibiscus heterophyllus is insignificant compared to the situation when weeds are allowed to encroach on Hibiscus heterophyllus habitat. Three of these weeds will be described and shown below as examples of how weeds are affecting populations of Hibiscus heterophyllus. We think the first two images would be on private land and possibly the plant in the third image is on council land. However, apart from it being dangerous to park where we did to get these photos, we do not feel that we could access the land where the plants are growing. It should however be noted that these are only examples from our local area and so the following three weed species should not be seen as a representative selection of weeds that threaten Hibiscus. Information on these weed species is from the Queensland Government website (W1) http://www.daff.qld.gov.au/26_8331.htm i. Climbing Asparagus Vine, Asparagus africanus. We are increasingly seeing plants being engulfed by Asparagus Fern in our immediate area. The first image below shows where a mature plant of Hibiscus heterophyllus has been smothered by Asparagus Vine. There is also evidence of Lantana as the photo shows but the plant that appeared to be the main cause of death of this hibiscus is Climbing Asparagus Vine. We had enjoyed seeing this hibiscus in bloom for over 10 years but we will not be seeing any flowers this coming spring.

Climbing Asparagus Fern is described as a garden plant that causes serious environmental problems when it escapes into bushland. It is an accomplished climber and easily scrambles over other vegetation up to 12m into the canopy and is a Class 3 declared pest plant under Queensland legislation (W1).

ii. Lantana Lantana camara The second photo below, taken in the next road to where we now live, shows that Lantana camara is alive and well and threatening a small pocket of remnant Hibiscus heterophyllus. Lantana can be seen in various locations in our local area and our observations indicate that it is the only species to be seen at these sites.

Lantana can grow as compact clumps, dense thickets and as scrambling and climbing vines. It is a Class 3 declared pest plant under Queensland legislation and a Weed of National Significance (W1).

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HIBISCUS HETEROPHYLLUS ALREADY SMOTHERED (1) OR BEI NG SMOTHERED (2,3) BY WEEDS

iii. Morning Glory, Ipomeae cairica We had not however previously seen Hibiscus heterophyllus being suffocated by Morning Glory, Ipomeae cairica, until we recently went to a site which we have been visiting for over 10 years. When we have had international visitors staying, we took them to this site to show them the best local example of a flourishing population of Hibiscus heterophyllus. Flowers could be seen up until January, which is longer than for other local sites. The extended flowering is possibly because the site is higher than other places where we have observed Hibiscus heterophyllus. As the third photo indicates, this is no longer a place to show off the beauty of our local Hibiscus heterophyllus plants. Not only were most of the plants in this site being smothered by Morning Glory, on our last visit we could see that any attempts by the hibiscus to ‘escape’ from the encroaching Morning Glory left the plant subject to attack by insect predators and so just the leaf ribs were often all that could be seen (Image 3). Morning Glory is described as a vigorous grower, developing into a thick, covering mat of vegetations, sometimes climbing 4-5 metres into the canopy. It is known to smother other vegetation. It is not a declared pest under Queensland legislation (W1). CONCLUSION: Sites within an hour’s drive from our home in the Brisbane Valley are experiencing a variety of threats to Hibiscus heterophyllus, even though the locations are some distance from each other. Destruction of plants by bulldozers or roadside spraying has resulted in the loss of plants, some with desirable features. However, the greatest threat is by far the rapid spread of weeds. Plants that have brightened spring for ourselves and for visitors are either dead from being smothered by Climbing Asparagus Fern or threatened by Lantana or Morning Glory. We feel it is important to bring our observations to the attention of members of the Hibiscus and Related Genera Study Group. It was not until we actually started to take and collate photos of Hibiscus heterophyllus in our local area that we realised the extent of the destruction of habitat that is occurring to what is our favourite species of native hibiscus.

HIBISCUS HETEROPHYLLUS IMAGES

Flowers in spring; calyx of bloom; bloom, buds and leaves close-up of bloom

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HIBISCUS ‘WIRRUNA’ AND HIBISCUS ‘PINK ICE’ In Newsletter 22/23b of June 2011, two cultivars of Hibiscus that had been grown since 2000 by Mrs Gill Muller of South Australia were discussed. Photographs from Gill were included. The first cultivar was ‘Wirruna’ which had been deliberately hybridised by Lyn Craven. The other plant, ‘Pink Ice’, was described as a chance hybrid in the garden of Jan Sked in Queensland. It was noted that it was interesting that these hybrids, derived from Australian East Coast species, are doing so well in Adelaide. While it is of interest that these two cultivars, bred from hibiscus species of the East Coast, have performed so well in Adelaide, there is another interesting fact about these two plants. These are the first cultivars to have been included in written records, Hibiscus ‘Wirruna’ in 1971 and Hibiscus ‘Pink Ice’ in 1976. While it was not until the 1970s that there were written records of these two cultivars, there were written records of the parents dating back to the 19th Century. Both plants had Hibiscus heterophyllus as one parent, with ‘Wirruna’ having a yellow form of Hibiscus heterophyllus as its parent and ‘Pink Ice’ a white form. Hibiscus splendens was the other parent of both cultivars. Hibiscus heterophyllus had been recorded in the Brisbane area in 1824 by Allan Cunningham, in 1828 by Charles Fraser and again in 1844 by Ludwig Leichhardt. Describing the vegetation along the Brisbane River, Cunningham noted that Hibiscus heterophyllus was very frequent on the immediate bank "clothed with a profusion" of flowers. However, this was not the first mention of this species. In the early 1800s, it had been grown by Napoleon’s wife Josephine at Malmaison outside Paris and had flowered there. These references were all to the white form of Hibiscus heterophyllus. Hibiscus splendens was described by the Colonial Botanist of New South Wales, Charles Fraser, as the King of all the Australian plants he had seen, with flowers that were the most delicate pink and crimson and which literally covered the plant. In 1828, he sent seed to the Royal Botanic Garden, Edinburgh and a seedling flowered there in 1830 (1).

HIBISCUS ‘WIRRUNA’ Hibiscus ‘Wirruna’ was described in Australian Plants, Vol. 6 of June 1971, pages 104 and 105. There was a photo of ‘Wirruna’ and there were photos of each of the parents, the yellow form of Hibiscus heterophyllus known as ‘Aureus’ and Hibiscus splendens. It was noted that ‘Wirruna’ was raised by Mr L. A. Craven of Black Rock, Victoria and that the name ‘Wirruna’ is an Aboriginal word which means ‘sunset’.

Photo: Mrs Gill Muller, South Australia

Lyn has recently noted that his reasons for making the cross were 1) out of sheer curiosity to see what would happen, and 2) to see if a novel cultivar might result. He was able to score a tick on each of these counts. Lyn further noted that he crossed a white-flowered form of Hibiscus heterophyllus with the same yellow plant. He describes the result a (perhaps predictable) cream which was not worth growing.

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Lyn has further advice: having a range of different flower colours with which to work, is the key to getting some good, novel garden plants. Plus some hardiness and adaptability of course!! The print record of 1971 was not the only time ‘Wirruna’ has been mentioned. The Australian Plant Names Index (APNI) currently shows the following records: Hibiscus 'Wirruna' nom. cult..

Elliot, W.R. & Jones, D.L., (1990) Encyclopaedia of Australian plants suitable for cultivation 5: 364 Harvey, G., Harrison, D. & Keena, C., (2008) Prospects for Developing Improved Native Hibiscus Cultivars. Australian Plants 24(197): 380 Keena, C. & G., (2008) Our Favourite Hibiscus. Australian Plants 24(197): 355

Comment: Parents Hibiscus splendens x H. heterophyllus -, Australian Cultivar Registration Authority records. : -

Text: Australian Plants 6, 104 (1971). 235194

SOME MORE IMAGES OF HIBISCUS ‘WIRRUNA’

HIBISCUS ‘PINK ICE’ Hibiscus ‘Pink Ice’ was described by Jan Sked in her 1976 book of plants for a native garden in the subtropics (2). As already noted, it is described as a hybrid between the pink H. splendens and white H. heterophyllus. It has a long flowering period in spring and summer. The large pink flowers have crimson centres and are produced in abundance all up the stems.

Photo: Mrs Gill Muller, taken in Adelaide, South Australia

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Jan has recently stated that from her recollections, Hibiscus ‘Pink Ice’ was grown from a seed from a white flowered form of H. heterophyllus, which had grown from a cutting taken at Donnybrook. At the same time, she had H. splendens also flowering in her garden. When the seedling developed, it looked different from its H. heterophyllus parent and Jan assumed that it was a cross between both the species in her garden, as there were no other Hibiscus anywhere in the vicinity. Jan gave cuttings of her plant to a local nursery and it was propagated for some time. Jan’s plant set seed and later she grew a number of seedlings from Hibiscus ‘Pink Ice’ and they developed into many different forms - some with dark green leaves, some with grey leaves, some pink, some white, some both pink and white. Jan planted a host of them in a nearby area of land, where they grew and flowered for many years and she also planted some around a local building. They were all very vigorous, as was their parent. Jan states that this would have been during the latter part of the 1970s. She took many photographic slides of my plant and its flowers, but she says that they have faded over the years and have lost their colour and clarity. Jan states that eventually she had to remove her plant, as it was a very hungry plant and seemed to suppress all the other plants around it. (NOTE: As Jan had given her plant to a nursery, it became more widely available although it is likely that Jan did not expect to see photos of it from Adelaide). The print record of 1976 was not the only time ‘Pink Ice’ has been mentioned. The Australian Plant Names Index (APNI) currently shows the following records: Malvaceae Hibiscus 'Pink Ice' nom. cult..

Elliot, W.R. & Jones, D.L., (1990) Encyclopaedia of Australian plants suitable for cultivation 5: 364 Harvey, G., Harrison, D. & Keena, C., (2008) Prospects for Developing Improved Native Hibiscus Cultivars. Australian Plants 24(197): 380 Keena, C. & G., (2008) Our Favourite Hibiscus. Australian Plants 24(197): 355

Comment: Parents Hibiscus splendens x H. heterophyllus -, Australian Cultivar Registration Authority records. : -

Text: Listed in Fairhill Native Plants - "Australian Native Plants for subtropical and tropical east-coast gardens" (1985). 235193 SOME MORE IMAGES OF HIBISCUS ‘PINK ICE’

SUMMARY: The flowering period Jan notes for ‘Pink Ice’ is longer in the subtropics than it is for either of the parents. The same applies in the subtropics to ‘Wirruna’. This is a feature that should be noted in relation to both these cultivars. Both cultivars were recorded in the 1970s. Both are still available and this is a testament to their hardiness and adaptability, features that Lyn Craven notes are essentials for good plants. REFERENCES 1. The Edinburgh New Philosophical Journal, Vol. 9, 1830, page 170. 2. J. M. Sked, L. S. Smith, E. Prescott. Planting a Native Garden in the Subtropics. Pine Rivers Branch, Society for Growing Australian Plants, Queensland Region Inc., 6th Edition, 1998. 1st edition 1976.

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